Abstract: Abatement of respiratory coal dust is facilitated by water spraying the dusty area with a system having at least about 50 ppm of the combination of a water soluble sulfonic acid salt and a nonionic surfactant having an HLB ranging from 12 to 14.

Abstract: The process of preparing thioethers by reacting aliphatic thioalcohols, e.g., mercaptans, including hydrogen sulfide with activated, alpha, beta unsaturated compounds ##STR1## capable of participating in the Michael Addition Rection* in which X is a suitable electron withdrawing group. The Addition, which is carried out in the presence of a catalytic base is greatly improved with respect to minimizing formation of side products by utilizing a specially selected catalyst comprising one or more cyclic tertiary nitrogen compounds having an excellent balance between reactivity and selectivity. The preparation of thioethers from acrylic acid derivatives especially esters (CH.sub.2 .dbd.CH--COOR', R'=C.sub.1 --C.sub.8) is preferred. The preparation of the dimethyl ester of 3,3'-thiodipropionic acid to result in dimethylthiodipropionate of relatively high purity is especially preferred.* See Vogel, PRACTICAL ORGANIC CHEMISTRY, p. 912-913, Third Enlarged Edition.